IEEJ Transactions on Industry Applications
Online ISSN : 1348-8163
Print ISSN : 0913-6339
ISSN-L : 0913-6339
Volume 115, Issue 4
Displaying 1-22 of 22 articles from this issue
  • Junichi Arai, Tuneyoshi Oohashi
    1995 Volume 115 Issue 4 Pages 361-364
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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  • Toshio Miyata, Shotaro Murakami, Noriyuki Watanabe
    1995 Volume 115 Issue 4 Pages 365-369
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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  • Masanao Kato
    1995 Volume 115 Issue 4 Pages 370-372
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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  • Seiji Kondo, Hideki Katayama
    1995 Volume 115 Issue 4 Pages 373-378
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    An auxiliary resonant commutated pole (ARCP) inverter can achieve not only so-called soft switching but also PWM control. The fluctuation of the neutral point voltage, however, causes commutation failure of the inverter.
    It was found by analytical and experimental results that flux vector following control for switching pattern generation gives larger value of the voltage fluctuation than sin-triangular wave comparison method. Then a new control scheme to maintain the neutral point voltage at a half of dc link voltage was proposed. The method utilizes the redundancy of zero voltage vector of the voltage source inverter. For the ARCP 3 phase inverter (AC output 200V, 4.5kVA) built and tested, the value of capacitors to keep the neutral point voltage with the control can be decreased to about 1/60 of that when no control is applied.
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  • Yoshitaka Ikeda, Rokusaburo Sakai, Kazuaki Asano, Takayuki Sakamoto
    1995 Volume 115 Issue 4 Pages 379-386
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    The resonant DC link invertors have been developed these years for avoiding the switching loss of the conventional multi-pulse PWM invertors. This paper proposes a three phase VVVF power invertor using resonant pulse density modulation for induction motor speed-control. The invertor is composed of a cascade connection of a resonant DC-DC convertor and a multi-pulse PWM invertor. The output waveform depends on the gate pulse patterns of the invertor valves. This paper proposes three kinds of pulse patterns for obtaining the outputs of trapezoidal waveform and of sinusoidal waveform, and describes also the experimental results. The V/f characteristics for induction motor speed-control and the regenerative braking operation will be examined and the circuit behaviors will be discussed.
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  • Hirotami Nakano, Tsuyoshi Murase, Satoshi Togasawa, Akira Nabae
    1995 Volume 115 Issue 4 Pages 387-393
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    A new theory of instantaneous reactive power compensation on three-phase power systems is proposed. The validity of the proposed theory is demonstrated by the simulation and experimental results.
    The proposed theory is based on a new concept, that is, a three dimensional cross vector which is newly proposed and defined in this paper. The three dimensional cross vector is the cross product of a voltage space vector and a instantaneous current space vector on three-dimensional rectangular coordinates. And an instantaneous reactive current space vector is easily detected by using the three-dimensional cross vector.
    Therefore, the proposed theory does not use any coordinate transformations, such as a rotating coordinate transformation or a three-phase to two-phase coordinate transformation. Hence, the instantaneous reactive power compensation system based on the proposed theory in this paper is essentially simpler than any conventional reactive power compensation system based on such coordinate transformations.
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  • Seok Kwon Jeong, Yasumasa Fujii, Takashi Sekiguchi
    1995 Volume 115 Issue 4 Pages 394-401
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    At the present time, almost all of the quick torque control of an induction motor is achieved by vector control or direct torque control methods using CSI (Current-Source Inverter) or VSI (Voltage-Source Inverter) controller. Compared with CSI, VSI has several advantages, such as simple structure, low cost and so on. Consequently, VSI is generally used in induction motor driving systems. However, very quick torque response is hardly attained in VSI systems without the detection of stator current information. This makes the simple structure of VSI rather complicated after all.
    In this paper, a new control method to realize very quick torque response of an induction motor system with VSI is proposed. The method developed here employs a PWM voltage-source inverter without the detection of stator current information. The method is based on the explicit mathematical analysis of the two transient terms of the current, and is formulated in a very simple arithmetic manner. For this control, the authors introduced a new concept of pulse addition on the input voltage of an induction motor. Through both numerical simulations and DSP (Digital Signal Processor) system-based experiments, the conceptual validity of the proposed method was successfully confirmed.
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  • Akira Chiba, Kouichi Ikeda, Fukuzou Nakamura, Tazumi Deido, Tadashi Fu ...
    1995 Volume 115 Issue 4 Pages 402-409
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Switched reluctance motors have been studied in twenty years but the applications have been limited to special cases. One of the main reasons of these limited applications is the complicated machine model and unclear operating characteristics of switched reluctance motors. Conventional synchronous motor models are not applicable because the current waveforms of switched reluctance motors include dc component and considerable amount of harmonics. A simple analytical model and normalized characteristics of switched reluctance motors are needed to express voltage, current and torque relationships.
    In this paper, the inductance variations of a switched reluctance motor are represented only by a fundamental component and a constant. Terminal voltage is also approximated as sinusoidal. With these approximations, the relationships of normalized voltages, currents and output powers are derived. It was found that the power to voltage ratio can be maximized at a particular voltage phase angle θv. It was also shown that there is another voltage phase angle θi, which maximizes power to current ratio. The most efficient operation of switched reluctance motors can be realized with the voltage phase angle between θi and θv. These analytical results were confirmed with experimental results of a test machine rated 2.2kW at a speed of 6, 000rpm.
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  • Yasuyuki Nishida
    1995 Volume 115 Issue 4 Pages 410-419
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    The harmonic pollution caused by ac-to-dc converters has been our great concern. To overcome the problem, several Power-Factor-Correction (PFC) converters have been developed and applied in practice in recent years.
    However, several power converter systems, such as motor drive system with a wide V/F control range, uninterruptible power supply system, and dc power supply system with an universal input voltage range, require an ac-to-dc converter or an off-line converter (pre-regurator) with a wide output-voltage control range to obtain high efficiency. But the most conventional PFC converters employ a Voltage-Fed or Current-Fed type topology and they have lower or upper limitation of the output-voltage control range. Thus, they do not realize sufficiently high system efficiency.
    On the other hand, a Buck/Boost converter has a wide control range of the output voltage and acts PFC operation under an appropriate control technique. Thus, the study of a possibility about the Buck/Boost ac-to-dc converter with PFC and a wide output-voltage control range is important to realize harmonic-free and efficient power conversion systems.
    In this paper, the author proposes a three-phase bridge-type ac-to-dc converter system with a high input power factor and a wide output-voltage control range. The controller of the proposed system includes following two new techniques. One is the “Pulse-Space-Modulation” to compensate modulation errors in conventional Pulse-Width-Modulation caused by dc current ripples or fluctuations of the current pulse amplitude. The other is a switching pulse pattern generator, using the idea of equivalent pulse current source for the bridge, to simplify the pulse pattern generation process.
    In the following, the paper describes the proposed converter system, the control and modulation principles, and experimental results that show the reliability and usefulness of the proposed Buck/Boost converter system. Finally, the paper concludes the contents of this paper.
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  • Takaharu Takeshita, Naofumi Nomura, Nobuyuki Matsui
    1995 Volume 115 Issue 4 Pages 420-427
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper presents a position sensorless drive of a brushless dc motor with a sinusoidal flux distribution. The estimation of position and emf is performed by using the integration of the current differences between the actual motor and model. The estimation speed is calculated by the differential calculus of the estimated position. The stability of the proposed algorithm and the design of the estimation gains are explained and it is shown that the parameter differences do not give serious effects on the estimation characteristics.
    In the experimental results using a 6-pole 1.2kW test motor, the speed control range from 35 to 1500rpm is obtained. To verify the proposed algorithm, the estimation and speed control characteristics are shown. Furthermore, the starting characteristics of the motor from arbitrary rotor position are shown.
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  • Takehisa Kohda, Koichi Inoue
    1995 Volume 115 Issue 4 Pages 428-435
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Based on the results of its inspection items, the failure diagnosis system identifies the cause of system failure. The role of failure diagnosis is to identify the system state currectly. However, diagnosis errors may be caused by sensor failure or operator errors, which lead to serious damage or unnecessary protective actions. The effect of an error depends on the system condition. In the design of failure diagnosis procedure, not only diagnosis error probability, but also its effect on the system must be considered.
    This paper proposes the optimization of failure diagnosis procedures based on diagnosis error loss. The optimal procedure that minimizes the expected loss caused by inspection errors is developed for two cases: one where all results of inspection items are given simultaneously and one where an inspection item is examinied sequentially. In the former case the optimal failure diagnosis logic is obtained, while in the latter case the optimal test sequence is obtained. Illustrative examples show the merits and details of the proposed method.
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  • Kazuto Sakai, Teruo Washizu
    1995 Volume 115 Issue 4 Pages 436-443
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    In variable speed drive applications, both the constant torque (low speed) and constant power (flux weakening) operating modes are required. As the magnet flux of a permanent magnet motor is fixed, the air-gap flux weakening is accomplished by applying a large d-axis current to drive at high speed. Therefore, efficiency of the motor is low and the permanent magnet is demagnetized irreversibly.
    In this paper, a new permanent magnet motor for flux weakening operation is proposed and the characteristics of the motor using a magnetic analysis are described. The new permanent magnet motor has a rotor mounting permanent magenets which are covered with a magnetic ring made of Fe-Si or SUS630. To evaluate no-load, load and flux weakening characteristics of the motors, the field analysis using a two dimensional finite element method has been performed.
    The results of analysis are shown that the new permanent magnet motor performs to the wide speed range of 2 times a maximum speed of a conventional motor.
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  • Jeong-Ho Shin, Kenji Fujiune, Tatsuya Suzuki, Shigeru Okuma, Koji Yama ...
    1995 Volume 115 Issue 4 Pages 444-451
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    To achieve high performance control of robot manipulator, one has to overcome disturbances added on each joint and nonlinear forces such as a frictional force, gravity, interacting force. To meet these ends, recently a method based on disturbance observer was proposed which is characteristic of the fact that it does not need inverse dynamics calculation and thus can be implemented with a simple microprocessor. However, this method depends on the intutional approach in determining the disturbance estimation filter, so more systematic approach is desirable. In this paper, we propose a new design approach of a two-degree-of-freedom compensator taking into account the robust stability. First of all, we clarify the internal structure of the generalized two-degree-of-freedom compensator. By using this structure, we can make a bridge between a generalized controller and the disturbance observer based controller. Secondly, based on the clarified structure we derive a robust stability condition, and propose a design algorithm of free parameter taking into account it. The proposed design algorithm is ease to execute and, as the result, we obtain the low order free parameter compared with the conventional design algorithm. Thirdly, we show that the clarified structure can also be regarded as an extended version of the conventional PD compensator by adopting an appropriate coprime factorization. Finally, we apply the proposed algorithm to a three-degree-of freedom direct drive robot, and show some experimental results to verify the effectiveness of the proposed algorithm.
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  • Tetumi Harakawa, Eizi Sumitani, Takuya Tosihiro, Kunio Sekiguchi, Hiro ...
    1995 Volume 115 Issue 4 Pages 452-460
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper presents that, in hot strip finishing mills, AC motor drive systems improve the strip tension control performance which results in better strip thickness accuracy than DC motor drive systems.
    Recently the AC motors are more widely used in many industrial fields including steel making process because of their higher response of speed control, higher reliability, and easier maintenance than DC motors. Here we consider the effect of using AC motors as rolling main motors from a point of view of strip thickness accuracy. We analyse the relation between speed control response of the strip tension control system and strip thickness accuracy with use of the Bode diagram and non-linear simulation. As a result we show that the higher response of AC motor speed control system can achieve the smaller strip tension deviation, furthermore makes it possible to get higher response of gage control system which turns more accurate strip thickness.
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  • Yoichi Sugita, Masahiro Kayama, Yasuo Morooka, Yutaka Saito
    1995 Volume 115 Issue 4 Pages 461-469
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Mathematical models used for control, such as for generating control references, have to be identical to the actual controlled objects to improve control accuracy. For this, their parameters are often tuned by model errors derived from the detected outputs of the controlled objects and calculated ones using the mathematical models. Therefore accurate identification between the model errors and appropriate tuning values of the parameters is necessary to complete tuning with small tuning numbers and no steady state errors.
    In this paper, we propose The Adjusting Neural Network (AJNN), which is the extended model of conventional Multi-layered Neural Networks (CNN), to identify the non-linear relationship between them accurately. AJNN consists of two Multi-layered Neural Networks, namely, the Error Calculation Neural Network (ECNN) is added in parallel to CNN, where the ECNN calculates the output error of CNN and subtracts it from the output of CNN, to obtain accurate tuning values. Training method for AJNN is also proposed, where modified Back-propagation developed for reducing the error of AJNN and the conventional Back-propagation for decreasing the output of ECNN to zero, are applied to AJNN alternately. Finally, AJNN is evaluated with the model tuning of temperature control for reheating furnace plants and demonstrated to be effective to improve the accuracy of tuning and decrease tuning numbers.
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  • Sakutaro Nonaka, Kunio Fujii, Sumio Hara
    1995 Volume 115 Issue 4 Pages 470-477
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    In this paper, a new brushless single-phase self-excited type half-speed synchronous motor which is combined with the voltage source inverter is presented. The diode is inserted into one phase of the stator winding, and then the stationary magnetic field is superimposed on the alternating magnetic field. The motor is compelled to run at exactly half synchronous speed. The rotor structure of the proposed motor are composed of the quadrature-axis (q-axis) squirrel-cage damper winding on the salient-pole. The proposed motor is very simple, robust and maintenance-free. The experimental results indicated that the motor has an availability for practical use.
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  • Hiro Takano, Keiji Hatanaka, Tohru Inoue
    1995 Volume 115 Issue 4 Pages 478-487
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Zoomlenses are adjusted by driving motors outside of lens barrels and reduction gear trains in a majority of camcorders. If built-in direct driving motors housed in the lens barrels with no protrusion were invented, more compact, lighter and lower-cost camcoders than coventional ones would be developed. A new motor satisfying such a tough requirements is proposed in this paper. A stator (lens barrel) and a rotor (variator lens) function as a female screw and a male screw, respectively. Then, switching currents of armature windings buried in the lens barrel sequentially, the rotor rotates and the lens is shifted to an optical axis direction. This motor is a kind of a permanent magnet synchronous motor driven by an inverter, but the stator is in screwed engagement with the rotor and a torque is directly converted to an axial force without gear trains. Such a principle has not yet been presented. Although the motor was developed only for camcorders, it would also be used for other apparatuses. Performance analysis of this motor is reported in the paper.
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  • H. Koharagi, K. Tahara, Y. Ishii, S. Suzuki
    1995 Volume 115 Issue 4 Pages 488-494
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    Small-sized, AC series commutator motors (universal motors) are used very much in small appliances such as vacuum cleaners and hand tools, because they offer advantages of high speed and low cost. In particular, motors for vacuum cleaners are being designed with smaller size, but higher speed and increased output power. Therefore, it is desirable to improve commutation performance, because it influences the brush lifetime.
    In this paper, a method to improve commutation performance of the motors is described. It is an exceptional armature winding form in which the turn number of the backward coil is less than that of the forward coil in the same slots. The commutation sequence determines which is the backward coil and which is the forward one. The configuration and operation of the exceptional armature winding form for universal motors are detailed. A factor to relate the commutation performance using the magnetic field and the commutation analyses is also described. The design theory is built up with respect to the exceptional armature winding form and usefulness of the method is verified for predicting brush lifetime with actual motors. The effect of the armature winding to improvement the brush lifetime is confirmed experimentally.
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  • Yukio Tsutsui, Toshiro Higuchi
    1995 Volume 115 Issue 4 Pages 495-500
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    This paper describes a novel suspension technique using high Tc superconductors and magnetic materials. For a field-cooled superconductor and an adjacent magnetic material, it was found that the usual inverse relationship between the attractive magnetic force and gap distance reverts to a direct relationship for small gap length. Thus, stable, non-contact suspension is possible within a certain gap range. This phenomenon was found for even a soft magnetic material possessing a minimal coercive force. Since remarkable reversals were observed for magnetic materials with diameters much smaller than that of the pinned area, it is considered that some of the pinned flux is subject to a “gathering effect” in the magnetic material. Stable, contact-less suspension of a 180g carbon steel weight under a high Tc superconductor was achieved using this technique.
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  • Moriaki Takechi, Sigenori Kuroda
    1995 Volume 115 Issue 4 Pages 501-507
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
    External magnetic disturbance has great influence on the quality of the image obtained by magnetic resonsnceimaging system because it causes a drift of magnetic resonance frequency. When a superconducting magnet in persistent current mode operation is exposed to external magnetic disturbance, current in the coil varies to keep linkage flux constant. The conventional analysis is usually formulated on condition of constant current and does not give correct evaluation of drift of magnetic field in the magnet. This paper proposes a method of numerical analysis of magnetic field considering conservation of linkage flux in a superconducting magnet under persistent currnt mode operation. This method is applied to evaluate drift of magnetic field in a supercconducting magnet for magnetic resonance imaging due to external magnetic disturbance. The results of the anlysis show good agreement with the experimental results.
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  • Masafumi Sakamoto, Akira Tozune
    1995 Volume 115 Issue 4 Pages 508-509
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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  • Hiroshi Yamada
    1995 Volume 115 Issue 4 Pages 510-511
    Published: March 20, 1995
    Released on J-STAGE: December 19, 2008
    JOURNAL FREE ACCESS
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